Fermentation of Monascus purpureus on bacterial cellulose-nata and the color stability of Monascus-nata complex

Abstract

Nata, a bacterial cellulose produced by Acetobacter aceti ssp. xylinum, was colored by means of fermentation with Monascus purpureus. Scanning electron microscopy (SEM) observations showed that the Monascus mycelium could grow through the cellulose network of nata. Rice powder as a major carbon source and monosodium glutamate (MSG) as a nitrogen source gave an appealing coloration after 12 d of fermentation at 30 °C. Compared to dyed nata, the color of the Monascus-nata complex had better resistance to washing, heat, freezing, acidification, and alkalization. A 66.1% decolorization was found under irradiation with 366 nm ultraviolet light after 36 h. The Monascus-nata complex has the potential to be a new vegetarian foodstuff.